The present invention relates to bicycle, and more specifically to a bicycle front fork and head tube mounting arrangement, which saves much bicycle manufacturing cost, and improves bicycle fabrication efficiency.
Nowadays, more and more people like to ride a bicycle. A bicycle is not only a personal transportation vehicle but also a sports means for physical exercise. In a bicycle, the head tube is supported on a ball bearing at the front fork, and a headlock ring assembly is installed in the top end of the head tube to lock the head tube, enabling the front fork to be rotated in the head tube. The head lock ring assembly is generally comprised of a top shell a bottom shell, a ball bearing cup, steel balls, etc. This structure of headlock ring assembly is complicated. The installation procedure of the head lock ring assembly is also complicated. During installation, the steel balls must be respectively mounted in the ball bearing cup and arranged in good order. Further, the dimentional tolerance of the parts of the headlock ring assembly is critical. If the parts do not fit one another perfectly, the parts must be separately ground to the desired fitness by labor.
The present invention has been accomplished to provide a bicycle front fork and head tube mounting arrangement, which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the bicycle front fork and head tube mounting arrangement comprises a front fork having a tubular top shaft and an annular bearing portion around the top shaft, a head tube sleeved onto the top shaft of the front fork and supported on a ball bearing in the annular bearing portion of the front fork, a locating ring supported on a ball bearing in the top end of the head tube around the top shaft of the front fork, a split screw cap tightened up with a locating screw and threaded into an inner thread in the locating ring, a rubber ring mounted in an inside annular groove in the split screw cap and disposed in close contact with the periphery of the top shaft of the front fork, and a tightening up screw threaded into a radial screw hole on the locating ring to hold down the split screw cap. According to another aspect of the present invention, the annular bearing portion of the front fork has a cross section curved inwards for positive of the front fork has a cross section curved inwards for positive positioning of the corresponding ball bearing.